package com.leo.book.netty.chapter10.xml.codec;

import java.io.StringWriter;
import java.nio.charset.Charset;

import org.jibx.runtime.BindingDirectory;
import org.jibx.runtime.IBindingFactory;
import org.jibx.runtime.IMarshallingContext;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.MessageToMessageEncoder;

/**
 * @author Administrator
 * @date 2014年3月1日
 * @version 1.0
 */
public abstract class AbstractHttpXmlEncoder<T> extends MessageToMessageEncoder<T> {
	IBindingFactory factory = null;
	StringWriter writer = null;
	final static String CHARSET_NAME = "UTF-8";
	final static Charset UTF_8 = Charset.forName(CHARSET_NAME);

	protected ByteBuf encode0(ChannelHandlerContext ctx, Object body) throws Exception {
		factory = BindingDirectory.getFactory(body.getClass());
		writer = new StringWriter();
		IMarshallingContext mctx = factory.createMarshallingContext();
		mctx.setIndent(2);
		mctx.marshalDocument(body, CHARSET_NAME, null, writer);
		String xmlStr = writer.toString();
		writer.close();
		writer = null;
		ByteBuf encodeBuf = Unpooled.copiedBuffer(xmlStr, UTF_8);
		return encodeBuf;
	}

	/**
	 * Calls {@link ChannelHandlerContext#fireExceptionCaught(Throwable)} to forward
	 * to the next {@link ChannelHandler} in the {@link ChannelPipeline} .
	 * 
	 * Sub-classes may override this method to change behavior.
	 */
	//@Skip
	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
		// 释放资源
		if (writer != null) {
			writer.close();
			writer = null;
		}
	}

}
